11. Karmaker S D, Biswas N M, Shaikh S K, et al.
Role of a large plasmid of Salmonella typhi
encoding multiple drug resistance. J Med
Microbiol. 1991; 34:149-151.
12. Jevanand H R, Ragavan P U M, Gunapathi R
S. Study of R-factors among multidrug
resistant Salmonella typhi. Indian J Med
Microbiol. 1997; 15:37-39.
13. Enderson E S, Lewis M J. Characterization of
transfer factor associated with the drug
resistance in Salmonella typhimurium. Nature
1995; 208:843-849.
14. Mandal S, Deb Mandal M, Pal N K. R-factor
in Salmonella enterica serovar Typhi: transfer
to and acquisition from Escherichia coli. Jpn J
Infect Dis. 2003; 56:65-67.
15. National Committee for Clinical Laboratory
Standards. Methods for dilution
antimicrobial susceptibility test for bacteria
that grow aerobically; approved standards-
fourth edition. M7-A4. Wayne (PA): The
Committee; 1997.
16. Birnboim H C, Doly J. A rapid alkaline
procedure for screening recombinant
plasmid DNA. Nucleic Acid Res. 1979; 7:1513-
1523.
17. Kado C I, Liu S T. Rapid procedure for
detection and isolation of large and small
plasmids. J Bacteriol. 1981; 145:1365-1373.
18. Maniatis T, Fritsch E F, Sambrook J.
Molecular cloning: A laboratory manual.
Cold Spring Harbor Laboratory, Cold Spring
Harbor, New York; 1982.
19. Sabherwal U, Chaudhary U, Saini S.
Multidrug-resistant Salmonella typhi in
Haryana in 1989-90. Indian J Med Res. 1992;
95:12-3.
20. Jesudason M V, John T J. Plasmid mediated
multidrug resistance in Salmonella typhi.
Indian J Med Res. 1992; 95:66-7.
21. Haldar K K, Basak S, Chakraborty A K, et al.
Transferable drug resistance in Salmonella
typhi strains isolated from an outbreak at
Calcutta in the recent past. J Indian Med
Assoc. 1995; 93:299-300.
22. Mandal S, Deb Mandal M, Pal N K.
Antibiotic resistance pattern of Salmonella
typhi isolates in Kolkata, India during 1991-
2001: a retrospective study. Jpn J Infect Dis.
2002; 55:58-59.
23. Mendoza-Medellin A, Rios-Chavez I,
Amaro-Robles D. Behavior of Escherichia coli
R factors in Salmonella typhi. Rev Latinoam
Microbiol. 1993; 35:77-85.
24. Datta N, Richards H, Datta C. Salmonella
typhi in vivo acquires resistance to both
chloramphenicol and cotrimoxazole. Lancet
1981; i:1181-1183.
25. Ridley M. The current use of antibiotics. In:
Ridley M, Phillips I, eds. The therapeutic use
of antibiotics in hospital practice. Edinburgh:
E & S. Livingstone, 1966:1-10.
26. Schwalbe R S, Hoge C W, Morris J G, et al. In
vivo selection for transmissible drug
resistance in Salmonella typhi during
antimicrobial therapy. Antimicrb Agents
Chemother. 1990; 34:161.
27. Kaul V. R-factor mediated multiple drug
resistance in Salmonella typhi strains isolated
for seven years. Indian J Med Microbiol. 1992;
10:107-113.
28. Richards H, Datta N. Transposons and
trimethoprim resistance. Br Med J. 1981;
282:1118-1119.
29. McKendrick M W, Smith H R.
Chloramphenicol resistance in the typhoid
bacillus. Br Med J. 1972; iii:329-331.